In order to evaluate the occurrence of Chlamydia trachomatis, we have examined samples of cervical swabs from 189 women (166 of which were symptomatic and the remaining 23 were asymptomatic with regard to chlamydial infection. Two specimens from the endocervical channel were collected and examined by immunofluorescent assay (DIF) and Chlamydia isolation. Detection of IgG and IgA antibodies specific to C. trachomatis was also effected by indirect immunofluorescent assay (IIF), in a cervical secretion sample. We succeeded in isolating chlamydia in 14 (8.4%) symptomatic and 3 (13%) asymptomatic women. The observation that the 152 symptomatic patients with negative results from chlamydia culture presented similar symptoms of disease, indicating that there is no specific symptom for genital infection caused by Chlamydia (p > 0.05). All the 13 (76.5%) positive endocervical specimens, as determined by cell culture and DIF reaction, presented more than 5 epithelial cells in the smears. These cells may represent an interference factor to the positivity of cell culture (p < 0.001). Antibodies of the IgG and/or IgA classes were detected in 11 (64.7%) out of 17 women with positive chlamydia culture, considering as positive the IIF titre of > or = 8. Consequently, this method can not be used as an alternative means of diagnosis, particularly in the earlier stages of chlamydial genital infections, since the presence of the antibodies depends on the phase of the infection and on the individual humoral immune response.